Cloud computing and its applications are effecting a qualitative shift in the way people communicate and share information. The underlying computer networks that support cloud computing can be divided into two major categories: intra-datacenter and inter-datacenter. Intra-datacenter networks interconnect the computing infrastructure (servers, disks) within the same building or among different buildings of a datacenter campus. Inter-datacenter networks connect multiple datacenters distributed at different geographic locations. Many modern high-speed data links use optical transmission technologies via optical fibers for both intra- and inter-datacenter networks.